Line-M Syrup is a combination pharmaceutical formulation containing Levocetirizine 2.5 mg and Montelukast 4 mg per dose, indicated for the management of allergic conditions such as allergic rhinitis and chronic urticaria in pediatric patients. Levocetirizine, a third-generation non-sedating antihistamine, selectively inhibits peripheral H1 receptors, thereby reducing symptoms like sneezing, nasal congestion, itching, and rhinorrhea. Montelukast, a leukotriene receptor antagonist, blocks the cysteinyl leukotriene receptor, mitigating airway inflammation and bronchoconstriction commonly associated with asthma and allergic reactions. The synergistic action of these agents provides comprehensive relief from allergic manifestations by targeting multiple inflammatory pathways. Line-M Syrup is particularly beneficial in pediatric patients requiring both antihistaminic and anti-inflammatory effects with a convenient oral liquid formulation to enhance compliance. It is generally well tolerated, with adverse effects being mild and infrequent, including headache, fatigue, or gastrointestinal discomfort. The syrup should be administered as per the prescribed dosage, and caution is advised in patients with hepatic or renal impairment. Line-M Syrup offers an effective therapeutic option for pediatric allergic disorders, improving quality of life by controlling symptoms and preventing exacerbations.